List of Alloys & profiles

List of Alloys & profiles

Alloy Wire International

Datasheet: Nilo® K

Nilo® K

A Nickel-Iron-Cobalt, controlled expansion alloy containing 29% Nickel. Its coefficient of expansion (which decreases with rising temperature to the inflection point), matches the expansion rate of borosilicate glasses and alumina ceramics.

Nilo® K is also known as Kovar, Dilver, and Pernifer 2918.

Available in all profile options

alloy featured image inconel Nilo® K

Key Features

Controlled coefficient of expansion (which decreases with rising temperature to the inflection point).
Matches the expansion rate of borosilicate glasses and alumina ceramics.

Typical Applications

Glass to metal seals in applications requiring high reliability or resistance to thermal shock, ie. high power transmitting valves


Designations

W.NR 1.3981
UNS K94610
AWS 094

Specifications

ASTM F15

Chemical Composition

ElementMin %Max %
Fe53.00 nominal
Ni29.00 nominal
Co17.00 nominal
Mn0.50
Si0.20
C0.04
Al0.10
Mg0.10
Zr0.10
Ti0.10
Cu0.20
Cr0.20
Mo0.20

Alloy Details

DensityMelting PointInflection PointThermal ConductivityCoefficient of Expansion
8.16 g/cm³1450 °C450 °C16.7 W/m• °C6.0 µm/m °C (20 – 100 °C)
4.6 – 5.2 µm/m °C (20 – 400 °C)
0.295 lb/in³2640 °F840 °F116 btu•in/ft2•h °F3.3 x 10-6 in/in °F (70 – 212 °F)
2.6 – 2.9 x 10-6 in/in °F (70 – 752 °F)

Heat treatment of finished parts

The Nilo alloys are usually supplied and used in the annealed condition (residual cold work distorts the coefficients of thermal expansion). Annealing times may vary due to section thickness. Oxidizing time and temperature to be selected depending on required oxide thickness.

TypeTemperatureTimeCooling
Anneal850 – 1000 °C
(1560 – 1830 °F)
0.5 HrAir or water
To prepare for glass to metal sealingDecarburization900 – 1050 °C
(1650 – 1920 °F)
1 HrAir or water
If a metal oxide interface is required (time and temperature depend on required oxide thickness)Oxidize600 – 1000 °C
(1110 – 1830 °F)
1 HrAir

Properties

Annealed
Approx. tensile strength<600 N/mm²<87 ksi
Approx. operating temperatureup to +400 °Cup to +750 °F
Hard Drawn
Approx. tensile strength700 – 900 N/mm²102 – 131 ksi
Approx. operating temperatureup to +400 °Cup to +750 °F

The above tensile strength ranges are typical. If you require different please ask.

*Trade name of Special Metals Group of Companies